Chelsea forward Eden Hazard and Manchester United striker Romelu Lukaku have been called up for Belgium's UEFA Nations League double-header despite injury concerns over the duo.

Lukaku missed last weekend's Premier League win over Bournemouth and also did not travel to Turin for Wednesday's Champions League defeat of Juventus due to a thigh muscle injury sustained in training a week ago, but has been named in Roberto Martinez's 25-man squad to face Iceland and Switzerland.

The Belgium boss did, however, open the door to Lukaku not teaming up with the rest of the squad depending on whether or not the 25-year-old featured in Sunday's Manchester derby.

"We are in contact with Manchester United over Romelu Lukaku," Martinez said. "We will make a final decision after the weekend."

Hazard has been struggling with a back injury that had seen him play just 26 minutes of Chelsea's four competitive games ahead of Thursday's Europa League encounter with BATE Borisov, before playing 62 minutes in their 1-0 win in Belarus.

One notable absentee from the squad was Lukaku's United teammate Marouane Fellaini. The 30-year-old has been limited to just four league starts under Jose Mourinho this season after sustaining a back problem while on international duty in September.

He made his first competitive appearance in almost a month when he came off the bench for the final 11 minutes of the game at Juve in midweek and had a hand in United's late winner, but Martinez will allow him to recover full fitness with his club during the international break.

"Marouane Fellaini is on his way back," Martinez said. "But not fully fit."

Chelsea's Eden Hazard and Manchester United's Romelu Lukaku have been prominent members of the Belgium squad for years. Pier Giorgio Giavelli/Isosport/MB Media/Getty Images

Martinez will head into the games looking to maintain his side's 100 percent record without an officially appointed assistant coach following the departure of, first, Graeme Jones and then Thierry Henry.

Reports have suggested former Celtic and Wigan Athletic man Shaun Maloney, who has already been working behind the scenes with the Belgium squad, could be promoted, but Martinez is in no hurry to find a permanent replacement.

"We want to introduce another member in our staff," Martinez said. "The target is March."